1. Field of the Invention
This invention relates to fluid transfer apparatus, and more particularly concerns a device for priming a siphon conduit which facilitates transfer of water between a source volume and a receiving location.
2. Description of the Prior Art
The hydrodynamic principle known as the siphon effect involves the transfer of a liquid by gravity effect from a source volume of the liquid to a receiving location at a lower elevation employing a liquid-filled conduit having a first extremity immersed below the surface of the source volume, an apogee located above the surface of said source volume, and a downstream second extremity located at an elevation generally below said first extremity. The conduit is considered to have upstream and downstream arm portions divided about the apogee, each arm portion terminating in its respective lower, or distal extremity. As long as the conduit remains liquid-filled, and the hydrostatic head of the downstream arm exceeds the hydrostatic head of the upstream arm, water will flow out of the source volume.
A source volume of water, whether confined within a vessel or natural reservoir, is generally bounded by a circuitous confining wall having an upper perimeter. Removal of water from the vessel can be achieved by pumping means or by gravity activated passage through an aperture in said wall located below the surface of the water. The siphon principle provides the advantage of removing water by gravity activated passage above the wall perimeter, thereby obviating the need for an aperture in the wall, or pumping means.
The primary difficulty encountered in establishing a siphon effect is in filling the conduit with the liquid which is to be acted upon. Several approaches for coping with this problem are disclosed in the prior art.
U.S. Pat. No. 4,041,971 to Newsteder describes a siphon starting device involving an inverted U-shaped rigid tube equipped with a manually operated pumping plunger interactive with the bottom extremity of the upstream arm of the U tube. The volume of Newsteder's pumping mechanism is greater than the volume of the U tube. Accordingly, one stroke of the plunger is intended to fill the tube, and begin the siphon effect. A shortcoming of this approach is that there is no assurance that air will be displaced from the U tube as water descends from the apogee into the downstream arm. Greater assurance of air displacement occurs only when the bottom extremity of the downstream arm is immersed below the liquid level in a receiving container.
U.S. Pat. Nos. 135,935; 919,079; 958,415; 4,112,963; 4,232,694 and 4,301,826 disclose manually operated piston pumps interactive with the downstream extremity of a flexible tube. The pump generally has a volume greater than the volume of the flexible tube, whereby a single stroke of the piston initiates the siphon effect. Once flow is initiated, the pump is either removed, or a by-pass conduit is provided for fluid flow.
Bellows-type siphon pumps of plastic construction are well known as emergency devices for removing gasoline from the fuel tank of an automobile. Such bellows pumps are generally interactive with the downstream arm of a flexible plastic tube, and include a check valve which ensures unidirectional fluid flow. In use, the distal extremity of the upstream arm is inserted into the fuel tank. With repeated manipulation of the bellows, fuel is caused to flow out of the fuel tank, through the bellows and into a downstream tube leading to a suitable receiving container.
The aforesaid siphon-initiating devices generally are not capable of lifting water a significant height to the apogee of the siphon tube, and neither are they generally capable of handling large volumes of water. Many potential applications exist for the siphon-based transfer of large volumes of water. For example, above-ground swimming pools often require removal of the contained water, and transfer of the water to a distant site for disposal. Such handling would best be achieved by employing a siphon tube comprised of long lengths of conventional garden hose of ½″ to ¾″ inside diameter. However, initiation of the siphon effect using tubing of such dimensions cannot easily be accomplished by prior art devices. Similar applications involve transporting water away from flooded regions and flooded basements of buildings.
It is accordingly an object of the present invention to provide a siphon initiating device suitable for transferring large volumes of water.
It is another object of this invention to provide a siphon initiating device useful with flexible siphon tubes of large diameter and considerable length.
It is a further object of the present invention to provide a siphon initiating device of the aforesaid nature which is interactive with conventional garden hose.
It is a still further object of this invention to provide a siphon initiating device of the aforesaid nature of durable, rugged construction amenable to low cost manufacture.
It is yet another object of the present invention to provide a siphon initiating device capable of lifting water a considerable height over the upper perimeter of a wall that retains a source volume of water to be acted upon.
It is an additional object of this invention to provide a siphon system which incorporates a device for initiating the operation of such system.
These objects and other objects and advantages of the invention will be apparent from the following description.